RESULTS OF RELIABILITY TEST PROGRAM ON LIGHT-WATER REACTOR PIPING

The Japan Atomic Energy Research Institute has conducted a piping reli ability test program to demonstrate the safety and reliability of ligh t water reactor primary piping. In this program, pipe fatigue test, le ak-before-break (LBB) verification test and pipe rupture test were car ried out to examine the integrity of piping, to verify the LBB and to demonstrate the effectiveness of protective measures against jet impin gement and pipe whip loads under a pipe rupture event. In the pipe fat igue test, a procedure to predict the fatigue crack growth was develop ed, and the integrity of piping during the plant service life was eval uated. In the LBB verification test, the pipe fracture test and the le ak rate test were performed to verify the LBB in the primary piping. I n the pipe rupture test, the influence of jet impingement on the targe t disk and the deformation behavior of whipping pipe and restraint wer e investigated. Using the test results, the jet impingement behavior a nd the effectiveness of pipe whip restraint were demonstrated.